Edoardo Carlesi (AIP)

Reverse Engineering the local Universe
When Nov 29, 2018 from 02:30 PM to 03:30 PM
  • Colloquium
Where SH Lecture Hall
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Cosmological simulations are a fundamental tool to probe the non linear regime of structure formation. However, the standard way of running does not usually allow for a direct comparison to the observable Universe, as the initial conditions (ICs) are generated using a random-phase realisations of the Lambda Cold Dark Matter (LCDM) matter power spectrum. In the Constrained simulations (CS) approach, galaxy peculiar velocity measurements are used to reconstruct the matter density field and generate a set of ICs whose final outcome matches the observed Universe.  In this way, we can consistently perform  "Near field cosmology" - i.e. we can extract cosmologically relevant information from the nearby Universe while also having a look at its past formation history.  First, I will describe some applications of this technique on large scales (up to approximately 200 Mpc), where I will show how our results can be used to reconstruct the scale-dependent bias parameter. I will then move on and discuss small scales application and the Local Group Factory, a numerical pipeline designed to generate Local Group-like objects within an environment akin to the observed one. I will show how such samples of simulated objects can be used to highlight the relation of some of the Local Group properties to the larger scale environment.  In the end, I will discuss some ongoing related projects, such as the HESTIA simulations.